JP2015081593A - Power generation plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generation plant that is a combination of a power generation system and an exhaust-heat power generation system generating electricity using exhaust heat from this power generation system, capable of optimizing a mode of taking in seawater for cooling and using the seawater.SOLUTION: A power generation plant G includes: a power generation system 1; an exhaust-heat power generation system 2 generating electricity using exhaust heat from the power generation system 1; and a coolant cooler 3. Seawater taken in on an upper layer that is a lower layer range of 20 m to 200 m from a sea level is supplied to a steam condenser 13 of the power generation system 1, a condenser 23 of the exhaust heat power generation system 2, and the coolant cooler 3 by a water cooling system 7 as seawater for cooling. A supply-quantity control unit 4 executes a first control to regulate a flow of the seawater passing through a condenser 13 for keeping an internal pressure of a steam circulation system 102 of the power generation system 1 within a predetermined range, and a second control to regulate a flow of the seawater passing through a heat exchanger 31 of the coolant cooler 3 for keeping a temperature of the coolant in an exhaust heat circulation system 6 within a predetermined range.

Description

  The present invention relates to a power plant in which a power generation system such as a thermal power generation facility and a waste heat power generation system that generates power using waste heat of the power generation system are combined.

  In a power plant equipped with a power generation system such as a thermal power generation facility, it is required to improve energy use efficiency. One means is to recover waste heat generated in the power generation system and use it as operating energy for other systems. Patent Document 1 discloses a technology that uses turbine oil supplied to a bearing of a steam turbine and waste heat of a generator cooler that cools a generator in a casing in a condensate system. In general, heat of turbine oil or the like is recovered by a cooling water (heat medium) circulation system and is heat discarded (waste heat) by the cooler of the cooling water. Energy utilization efficiency can be improved by using heat.

  There is also known a power plant including a waste heat power generation system that generates power using the waste heat. The waste heat power generation system includes an evaporation / condensation cycle using a low boiling point liquid as a working medium, and a waste heat turbine rotated by the working medium in a vapor state. Waste heat or the like of the turbine oil is used to evaporate the working medium. According to such a power plant, since the power generation is performed by the original power generation system and the waste heat power generation system, the power generation amount can be increased.

JP 2004-36535 A

  In power plants, seawater is exclusively used as cooling water for condensers and cooling water for the coolers. How the cooling seawater is taken and distributed to the power generation system and the waste heat power generation system affects the operating cost and efficiency of the power plant.

  In view of the above problems, an object of the present invention is to collect seawater for cooling in a power generation plant in which a power generation system and a waste heat power generation system that generates power using waste heat of the power generation system are combined. The purpose is to optimize the mode of use.

  A power generation plant according to one aspect of the present invention uses a power generation system including a steam turbine, a condenser, and a heating source, and a steam circulation system for circulating water or steam through the power generation system, and waste heat of the power generation system. A waste heat power generation system including a waste heat turbine, an evaporator and a condenser, a heat medium cooler including a heat exchanging unit, and a heat medium circulation system, wherein the steam A waste heat circulation system including a heat recovery unit that recovers waste heat of heat generated by the operation of the turbine, a heat release unit that releases heat in the evaporator and the heat exchange unit, and 20 m to 200 m from the sea surface The young deep water cooling system that takes in seawater in the younger deep layer that is the lower layer of the water and drains the seawater through the condenser, the condenser, and the heat exchange unit, and the heat of the waste heat circulation system Medium and the above-mentioned young deep water Control means for controlling the flow rate of the seawater in the rejection system, the control means for maintaining the pressure in the steam circulation system within a predetermined range, the condenser of the young deep water cooling system In order to maintain the temperature of the heating medium in the waste heat circulation system within a predetermined range, at least the heat exchange part of the young deep water cooling system is adjusted to adjust the flow rate of the seawater passing through At least one of the second control for adjusting the flow rate of the seawater passing therethrough is executed. Preferably, the control means executes both the first control and the second control.

  According to this configuration, it is equipped with a young deep water cooling system that takes in seawater from a young deep layer that has good water quality and is rarely inhabited by marine organisms such as jellyfish and shellfish. Adhesion can be suppressed. In addition, when the control means performs the first control, the pressure in the steam circulation system can be maintained within a predetermined range, thereby maintaining the vacuum efficiency of the condenser at a high level. it can. Furthermore, since the temperature of the heat medium is maintained within a predetermined range by the control means performing the second control, the cooling efficiency of the heat medium can be increased. In addition, the amount of seawater used is an amount sufficient to maintain the pressure in the steam circulation system within a predetermined range in the condenser, and the temperature of the heat medium in the heat exchanger is within a predetermined range. The amount of water used (water intake) can be minimized because the amount is limited to an amount sufficient to maintain the inside. Accordingly, it is possible to suppress facility operation costs and the like while enjoying the merit of water intake from the above-mentioned younger generation.

  In the above-described configuration, it is desirable that the power generation system is configured such that the temperature of the cooling water introduced into the condenser is limited within a certain temperature range.

  Usually, the cooling water introduced into the condenser is seawater near the sea level. For this reason, the temperature of the cooling water changes depending on the season, and this change in water temperature affects the vacuum efficiency of the condenser. The seawater temperature in the younger layers is lower than that near the sea surface, and the temperature range is constant throughout the season. Therefore, the power generation system can be made highly efficient by taking seawater from a young deep region having seawater temperature that does not affect the vacuum efficiency of the condenser.

  In the above configuration, the apparatus further includes a pressure sensor disposed on an outlet side of the steam turbine in the steam circulation system, and the first control of the control means is performed when a detection value of the pressure sensor is lower than a predetermined reference value The flow rate of seawater passing through the condenser is decreased with respect to a predetermined reference flow rate, and when the detected value is higher than the reference value, the flow rate of seawater is increased with respect to the reference flow rate. Control is desirable.

  According to this configuration, the degree of vacuum of the steam circulation system is monitored by the pressure sensor, and the flow rate of the seawater passing through the condenser can be optimized based on the monitoring result.

  In the above configuration, the waste heat circulation system includes an upstream side of the evaporator pipe passing through the evaporator, a heat exchange part pipe passing through the heat exchange part, and the evaporator pipe and the heat exchange part pipe. An outlet pipe connecting the heat recovery part, a downstream pipe connecting the evaporator pipe and the heat exchanging part pipe, and a return pipe connecting the heat recovery part, and arranged in the return pipe, A temperature sensor for detecting the temperature of the heat medium is further provided, and the second control of the control means is configured such that when the detected value of the temperature sensor is higher than a predetermined reference temperature, the flow rate of seawater passing through the heat exchange unit It is desirable to include a control to increase the value with respect to a predetermined reference flow rate.

  According to this configuration, the temperature of the heat medium in the return pipe can be monitored by the temperature sensor, and the flow rate of the seawater passing through the heat exchange unit can be optimized based on the monitoring result.

  In the above configuration, the waste heat circulation system further includes a short-circuit pipe that directly connects the upstream merging portion and the downstream merging portion, and the second control of the control means has a detection value of the temperature sensor being predetermined. It is desirable to include control for increasing the flow rate of the heating medium passing through the short-circuit pipe when the temperature is lower than the reference temperature.

  According to this configuration, since the short-circuit pipe is further provided as a circulation path of the heat medium, it is easy to perform control for maintaining the temperature of the heat medium within a predetermined range in the waste heat circulation system.

  According to the present invention, in a power generation plant in which a power generation system and a waste heat power generation system that generates power using waste heat of the power generation system are combined, an aspect of intake and use of seawater for cooling is optimized. be able to.

It is a block diagram showing roughly the composition of the power plant concerning one embodiment of the present invention. It is a figure which shows the concept of young deep water. It is a functional block diagram of the supply amount control part shown in FIG. It is a flowchart which shows operation | movement of a supply amount control part. It is a flowchart of condenser seawater flow control. It is a flowchart of waste heat circulation system cooling water temperature control.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram schematically showing a configuration of a power plant G according to an embodiment of the present invention. The power plant G is a power plant using young deep water described later as cooling seawater in the cooling system, and includes a power generation system 1, a waste heat power generation system 2, a cooling water cooler 3 (heat medium cooler), and a supply amount. The control part 4 (control means), the adjustment part 5, the waste heat circulation system 6, and the young deep water cooling system 7 are provided.

  The power generation system 1 is a commercial power generation facility including a steam power generation facility. As the power generation system 1, for example, a power generation system including equipment for oil thermal power generation, coal thermal power generation, or LNG thermal power generation can be exemplified. The power generation system 1 includes a boiler 10 (heating source), a steam generator 11, a steam turbine 12, a condenser 13, a feed pump 14, an equipment cooler 15, a combustion gas passage 101, and a steam circulation system as a schematic equipment configuration. 102.

  The steam circulation system 102 is a closed circulation line that is filled with pure water and circulates water or steam through the steam generator 11, the steam turbine 12, the condenser 13, and the feed water pump 14. The boiler 10 generates high-temperature combustion gas using petroleum, coal, LNG, or the like as fuel and supplies it to the combustion gas passage 101. The combustion gas passage 101 and the steam circulation system 102 exchange heat in the steam generator 11, and water sent to the steam generator 11 through the steam circulation system 102 by the feed water pump 14 is converted into steam by the heat exchange. The This steam is supplied to the blade portion of the steam turbine 12, and the steam turbine 12 is rotated about the axis of the rotation shaft. A rotating shaft of a generator rotor (not shown) is connected to the rotating shaft of the steam turbine 12, and electric power is generated by the rotation of the generator rotor accompanying the rotation of the steam turbine 12. The steam circulation system 102 is introduced into the condenser 13 on the downstream side of the steam turbine 12. In the condenser 13, heat is exchanged between the steam in the steam circulation system 102 and the cooling water (in this embodiment, young deep water), and the steam is converted into water.

  A pressure sensor 41 that detects the pressure in the steam circulation system 102 is disposed on the outlet side (downstream side) of the steam turbine 12 in the steam circulation system 102. The operation efficiency of the steam turbine 12 tends to become better as the pressure difference between the inlet side (upstream side) and the outlet side (condenser 13) of the steam turbine 12 in the steam circulation system 102 increases. Therefore, the pressure in the steam circulation system 102, particularly the degree of vacuum of the condenser 13, greatly affects the system efficiency of the power generation system 1. The pressure sensor 41 is arranged to monitor whether or not the pressure in the steam circulation system 102 (condenser 13) is maintained within an appropriate range.

  Although the operation efficiency of the steam turbine 12 increases as the vacuum degree of the condenser 13 increases, it reaches a peak when the vacuum degree reaches a certain value. This is because as the degree of vacuum is increased, it is necessary to increase the area of the heat exchanging portion or increase the amount of cooling water in the condenser 13, which increases equipment costs and operating costs. Therefore, there is no need to increase the degree of vacuum. The degree of vacuum changes with temperature. Here, the degree of vacuum of the condenser 13 can vary depending on the temperature of seawater that serves as cooling water in the condenser 13. When the temperature of the cooling water increases, the degree of vacuum tends to decrease, and when the temperature of the cooling water decreases, the degree of vacuum tends to increase. For this reason, it is desirable to select the water temperature of the seawater introduced into the condenser 13 so that the degree of vacuum (pressure) of the steam circulation system 102 (condenser 13) can be maintained in an appropriate range.

  The device cooler 15 is arranged to cool various devices (including the steam turbine 12 and the generator described above) included in the power generation system 1. For example, the turbine oil supplied to the bearing of the steam turbine 12 is cooled in the equipment cooler 15. In addition, cooling of bearing oil such as the feed water pump 14 and a fuel pushing fan and hydrogen gas for cooling the generator in the casing is also performed in the equipment cooler 15. In other words, the device cooler 15 is a device for recovering waste heat of heat generated by the operation of the steam turbine 12, and by extension, waste heat of heat generated by device operation of the power generation system 1. Waste heat recovered by the equipment cooler 15 is transferred to the waste heat power generation system 2 by a waste heat circulation system 6 to be described later and used as a heat source for power generation.

  The waste heat power generation system 2 is a system that generates power using the waste heat of the power generation system 1, and includes an evaporator 21, a waste heat turbine 22, a condenser 23, a circulation pump 24, and a working medium circulation system 25. The working medium circulation system 25 is a closed circulation line that sequentially passes through the evaporator 21, the waste heat turbine 22, and the condenser 23. The working medium circulation system 25 is filled with a low-boiling working medium having a vaporization temperature of about 30 ° C., for example, chlorofluorocarbon, and the working medium circulates inside the working medium circulation system 25 by a circulation pump 24.

  In the evaporator 21, the working medium is given heat and converted into steam. The heat source is waste heat of the power generation system 1 collected by the equipment cooler 15. This steam is supplied to the blade portion of the waste heat turbine 22, and the waste heat turbine 22 is rotated about the axis of the rotation shaft. A rotating shaft of a generator rotor (not shown) is connected to the rotating shaft of the waste heat turbine 22. Thereafter, the working medium in the vapor state is introduced into a condenser 23 disposed on the downstream side of the waste heat turbine 22 and is converted into a liquid state by being cooled. The cold heat source is young deep water.

  The waste heat circulation system 6 is a cooling water (heat medium) circulation system, and includes a heat recovery unit that recovers waste heat and a heat release unit that dissipates the recovered heat. The cooling water cooler 3 includes a heat exchange unit 31 that cools the cooling water circulating in the waste heat circulation system 6. The cold heat source in the heat exchange unit 31 is young deep water. The heat recovery unit of the waste heat circulation system 6 is disposed in the equipment cooler 15 of the power generation system 1, and the heat release unit is disposed in the evaporator 21 and the cooling water cooler 3 of the waste heat power generation system 2.

  More specifically, the waste heat circulation system 6 includes an evaporator pipe 61 that passes through the evaporator 21, a heat exchange section pipe 62 that passes through the heat exchange section 31 of the cooling water cooler 3, and a short circuit that does not pass through any device. And a pipe 63. The evaporator pipe 61, the heat exchange section pipe 62, and the short-circuit pipe 63 are pipes arranged in parallel, and merge with each other on the upstream side and the downstream side of these pipes. In FIG. 1, these merging portions are represented as an upstream merging portion 601 and a downstream merging portion 602. Further, the waste heat circulation system 6 includes an outward piping 64 that connects the upstream junction 601 and the device cooler 15, and a return piping 65 that connects the downstream junction 602 and the appliance cooler 15.

  In the equipment cooler 15, a heat recovery unit 6A of the waste heat circulation system 6 is arranged. The upstream end of the forward piping 64 is connected to the downstream side of the heat recovery unit 6A, and the downstream end of the return piping 65 is connected to the upstream side of the heat recovery unit 6A. The evaporator pipe 61 is provided with a first heat release part 6B1, and the heat exchange part pipe 62 is provided with a second heat release part 6B2. The first heat release part 6B1 is arranged in the evaporator 21 and the second heat release part 6B2 is arranged in the cooling water cooler 3. A cooling water circulation pump 66 is provided in the middle of the outward piping 64. The cooling water circulates in the waste heat circulation system 6 by driving the cooling water circulation pump 66.

  The cooling water circulating inside the waste heat circulation system 6 exchanges heat with waste heat of various devices of the power generation system 1 in the device cooler 15 in the heat recovery unit 6A, and the temperature is raised to about 60 ° C. The cooling water whose temperature has been raised is transferred to the downstream side by the cooling water circulation pump 66 and travels toward the first heat release part 6B1 and the second heat release part 6B2. In the first heat release part 6B1, the heated cooling water exchanges heat with the working medium of the working medium circulation system 25 and converts the working medium into steam. In the second heat release unit 6B2, the heated cooling water is heat-exchanged with the young deep water and cooled. The cooling water cooled by these heat exchanges goes to the heat recovery section 6A through the return pipe 65.

  A temperature sensor 42 that measures the temperature of the cooling water (heat medium) that circulates inside the waste heat circulation system 6 is disposed in the return pipe 65 of the waste heat circulation system 6. In the state where the cooling water passes through the waste heat power generation system 2 and reaches the return pipe 65, if the temperature of the cooling water is too high, the amount of heat that can be recovered in the equipment cooler 15 is reduced, and the power generation system 1 is cooled. Performance decreases. On the other hand, the fact that the temperature of the cooling water is below a certain value means that the cooling water is excessively cooled in the cooling water cooler 3. In other words, the young deep water is excessively used, which is not desirable. The temperature sensor 42 is arranged to monitor whether or not the cooling water in the return pipe 65 of the waste heat circulation system 6 is maintained at an appropriate temperature.

  The young deep water cooling system 7 is a system that supplies the young deep water as a cooling medium to the power generation system 1, the waste heat power generation system 2, and the cooling water cooler 3. The young deep water cooling system 7 takes seawater (young deep water) in the young deep layer, which is a lower range of 20 m to 200 m from the sea level, and the condenser 13 of the power generation system 1 and the condenser 23 of the waste heat power generation system 2. And the said seawater is drained via the heat exchanger 31 of the cooling water cooler 3.

  The young deep water cooling system 7 includes an intake pipe 71, a condenser pipe 72, a cooler pipe 73, a condenser pipe 74, a water discharge pipe 75, and a young deep water pump 76. The intake pipe 71 is a pipe for taking seawater from a young depth. The condenser pipe 72 is a pipe extending from the downstream end of the intake pipe 71 to the upstream end of the water discharge pipe 75 via the condenser 13. The cooler pipe 73 is a pipe that extends from the downstream end of the water intake pipe 71 to the upstream end of the water discharge pipe 75 via the cooling water cooler 3. The condenser pipe 74 is a pipe that branches from the cooler pipe 73 on the upstream side of the cooling water cooler 3 and merges with the cooler pipe 73 on the downstream side of the cooling water cooler 3 via the condenser 23. The water discharge pipe 75 is a pipe for returning the young deep water that has been heat-exchanged in each pipe to the sea. The young deep water pump 76 takes the young deep water from the upstream end of the intake pipe 71, transfers the young deep water in the young deep water cooling system 7, and transfers the young deep water from the downstream end of the water discharge pipe 75. Generate power.

  The young deep water flowing through the condenser pipe 72 exchanges heat with the steam flowing through the steam circulation system 102 in the condenser 13 to condense the steam into water. The cooler pipe 73 includes the heat exchange unit 31 described above inside the cooling water cooler 3, and the young deep water flowing through the cooler pipe 73 is connected to the heat exchange unit pipe 62 (second heat release unit 6 B 2) in the heat exchange unit 31. Heat exchange with the flowing cooling water is performed to lower the temperature of the cooling water. The young deep water flowing through the condenser pipe 74 exchanges heat with the vaporized working medium flowing through the working medium circulation system 25 in the condenser 23 to convert the working medium into a liquid.

  FIG. 2 is a diagram showing the concept of young deep water. In general, deep water refers to seawater that exists in a region 200 m or more deeper than the seawater surface, and is defined as seawater that does not reach sunlight and does not mix with surface seawater. Seawater existing within a depth of 20 m from the seawater surface can be said to be surface water that is well received by sunlight and affected by wind and waves. Young deep water is defined as seawater that exists between these deep water and surface water. That is, seawater existing between a depth of 20 m that is not affected by wind and waves and a depth of 200 m, the limit of sunlight reaching the sea, is defined as young deep water. In the present invention, this young deep water is defined as a power plant. Used as cooling water for G. This young deep-sea water has good water quality, and marine organisms such as jellyfish and shellfish are hardly inhabited, so it is possible to prevent marine organisms from entering and attaching to the power plant.

  The seawater temperature of the young deep layer water includes a temperature range (for example, a constant temperature range of 18 ° C. or lower) in which the condenser vacuum degree is in an appropriate range throughout the year. Can take water. The young deep layer water having the water temperature in the desired temperature range is supplied to the condenser 13 by the young deep layer water cooling system 7 and exchanges heat with the steam in the steam circulation system 102. The power generation system 1 is set so that the degree of vacuum of the condenser 13 is in an appropriate range and the efficiency of the steam turbine 12 is optimized when cooling water having the water temperature is given. That is, on the premise of the structure and performance of the condenser 13 that is used, the pressure on the inlet side and the pressure on the outlet side of the steam turbine 12 in the steam circulation system 102 are supplied to the condenser 13 in the cooling water in the temperature range. Is set so that the power generation system 1 is optimized. Therefore, the power generation efficiency of the power generation system 1 can be maximized by supplying the young deep water.

  The water temperature of the young deep water after the heat exchange in the condenser 13 is about 25 ° C to 30 ° C. With such a water temperature, there is little temperature difference with the water temperature of the sea surface layer, and water can be discharged to the surface layer. For this reason, in this embodiment, as shown in FIG. 2, while the intake of the intake pipe 71 of the young depth water cooling system 7 is arrange | positioned in a young depth, the outlet of the discharge pipe 75 is arrange | positioned in the surface layer. Thus, by using the young deep water, there is an advantage that the countermeasure for the hot waste water treatment which is a problem in the power plant is substantially unnecessary or can be significantly reduced.

  The adjustment unit 5 includes first, second, third, fourth, fifth, sixth, and seventh valves 50, 51, 52, 53, 54, 55, and 56, and flows through the young deep water cooling system 7. The flow rate and flow path of the young deep water and the flow rate and flow path of the cooling water flowing through the waste heat circulation system 6 are adjusted. These first to seventh valves 50 to 56 are flow rate adjusting valves, and the supply amount control unit 4 controls the opening and closing and the opening degree (flow rate).

  The first valve 50 is disposed in the condenser pipe 72 of the young depth water cooling system 7 and adjusts the flow rate of the young depth water supplied to the condenser 13. The first valve 50 may be disposed downstream of the young deep water pump 76 and upstream of the branch portion between the condenser pipe 72 and the cooler pipe 73. The second valve 51 is disposed in the cooler pipe 73 and adjusts the flow rate of the young deep water supplied to the cooling water cooler 3 and the condenser 23. Note that a booster pump 57 and a third valve 52 are attached to the cooler pipe 73 in parallel with the second valve 51. The 4th valve | bulb 53 is arrange | positioned at the heat exchange part piping 62 of the waste heat circulation system 6, and adjusts the flow volume of the cooling water which passes the cooling water cooler 3 (2nd heat discharge | release part 6B2). The fifth valve 54 is disposed in the short circuit pipe 63 and adjusts the flow rate of the cooling water passing through the short circuit pipe 63. The 6th valve | bulb 55 is arrange | positioned at the evaporator piping 61, and adjusts the flow volume of the cooling water which passes the evaporator 21 (1st heat discharge | release part 6B1). The seventh valve 56 is disposed downstream of the branch portion of the condenser pipe 74 and upstream of the cooling water cooler 3 in the cooler pipe 73, and passes through the cooling water cooler 3 (heat exchange unit 31). Adjust the water flow rate.

  The supply amount control unit 4 controls the operations of the first to seventh valves 50 to 56, the young deep water pump 76 and the booster pump 57 to maintain the pressure in the steam circulation system 102 within a predetermined range. In order to maintain the temperature of the cooling water in the waste heat circulation system 6 within a predetermined range, the first control for adjusting the flow rate of the young deep layer water passing through the condenser 13 of the young deep water cooling system 7 is performed. 2nd control which adjusts the flow volume of the young deep layer water which passes the heat exchange part 31 of the water cooler 3 is performed. During the second control, the supply amount control unit 4 also controls the flow rate of the cooling water in the waste heat circulation system 6.

  FIG. 3 is a functional block diagram of the supply amount control unit 4. The supply amount control unit 4 is an arithmetic unit composed of a personal computer or the like, and by executing a predetermined program, the flow rate control unit 43, the vacuum degree determination unit 44, the temperature determination unit 45, the pump control unit 46, and the reference data It operates so as to functionally include the storage unit 47.

  The flow rate control unit 43 controls the opening and closing of the first to seventh valves 50 to 56 and the opening degree (flow rate) to thereby control the flow rate and flow path of young deep water flowing through the young deep water cooling system 7, and waste heat circulation. The flow rate and flow path of the cooling water flowing through the system 6 are adjusted. Based on the detection value of the pressure sensor 41, the degree of vacuum determination unit 44 has the degree of vacuum on the outlet side of the steam turbine 12 in the steam circulation system 102 (the degree of vacuum of the condenser 13) within a predetermined reference value range. It is determined whether or not. Based on the detection value of the temperature sensor 42, the temperature determination unit 45 determines whether or not the cooling water temperature near the downstream junction 602 in the waste heat circulation system 6 is within a predetermined reference temperature range. The pump control unit 46 controls the drive of the young deep water pump 76 to adjust the total amount of young deep layers flowing through the young deep water cooling system 7. Furthermore, the pump control unit 46 controls the driving of the booster pump 57 as necessary, so that the flow rate of the cooling water in the waste heat circulation system 6 and the young deep layer water passing through the heat exchange unit 31 of the cooling water cooler 3 is controlled. Adjust.

  The reference data storage unit 47 stores the above-described reference value of the degree of vacuum, the reference temperature, and the allowable reference range defined by the characteristics of the power plant G. In addition, the reference data storage unit 47 stores the reference flow rate of the young deep water that flows to the condenser 13, the condenser 23, and the heat exchange unit 31.

  When the degree-of-vacuum determination unit 44 determines that the detected value of the pressure sensor 41 is lower than a predetermined reference value, the flow rate control unit 43 sets the flow rate of the young deep water passing through the condenser 13 to the reference flow rate. Decrease. On the other hand, when the degree-of-vacuum determination unit 44 determines that the detection value of the pressure sensor 41 is higher than the reference value, the flow rate of young deep water is increased with respect to the reference flow rate (first control).

  Further, the flow rate control unit 43 allows the young deep layer water to flow through the heat exchange unit 31 of the cooling water cooler 3 when the temperature determination unit 45 determines that the detection value of the temperature sensor 42 is higher than a predetermined reference temperature. Alternatively, control is performed to increase the flow rate of the young deep water with respect to a predetermined reference flow rate. On the other hand, when the temperature determination unit 45 determines that the detected value of the temperature sensor 42 is lower than a predetermined reference temperature, the flow rate control unit 43 performs control to increase the flow rate of the cooling water that passes through the short-circuit pipe 63. (Second control).

  Subsequently, the flow control operation of the young deep water (seawater) in the young deep water cooling system 7 by the supply amount control unit 4 and the flow control operation of the cooling water in the waste heat circulation system 6 are illustrated in FIGS. 4 to 6. This will be described based on the flowchart. In the normal operation state, the opening degree of the first valve 50 is adjusted so that the reference flow rate seawater is supplied to the condenser 13. In the cooling water cooler 3, it is assumed that the fourth valve 53 and the seventh valve 56 are operated at the minimum opening in the normal operation state. In addition, the temperature adjustment of the cooling water in the waste heat circulation system 6 is assumed to be maintained at the reference temperature by the opening balance between the fifth valve 54 and the sixth valve 55.

  Referring to FIG. 4, when a predetermined sampling period (for example, every 1 to 10 minutes) arrives (YES in step S1), supply amount control unit 4 detects a detected value from pressure sensor 41, that is, steam circulation system 102. The value of the degree of vacuum on the outlet side of the steam turbine 12 (the degree of vacuum of the condenser 13) is acquired (step S2). Subsequently, the degree-of-vacuum determination unit 44 compares the detected value with a reference value stored in the reference data storage unit 47, and whether or not the detected value matches the reference value or a predetermined value. It is determined whether it is within the reference range (step S3).

  When the detected value is not the reference value or the reference range (NO in step S3), the supply amount control unit 4 controls the condenser seawater flow rate in order to return the detected value to the reference value or the reference range. (Step S20). On the other hand, when the detected value is the reference value or the reference range (YES in step S3), the detected value from the temperature sensor 42, that is, the value of the cooling water temperature near the downstream junction 602 in the waste heat circulation system 6. Is acquired (step S4). Subsequently, the temperature determination unit 45 compares the detected temperature value with the reference temperature stored in the reference data storage unit 47, and whether or not the detected temperature value matches the reference temperature, or the reference It is determined whether it is within the range (step S5).

  When the detected temperature value does not match the reference temperature or the reference range (NO in step S5), the waste heat circulation system cooling water temperature control is performed to return the cooling water temperature to the reference temperature or the reference range. (Step S30).

  FIG. 5 is a flowchart showing details of the condenser seawater flow rate control (first control) in step S20. First, the degree-of-vacuum determination unit 44 stores the pressure data acquired in the previous step S2 in a memory (not shown) (step S21). Next, the degree-of-vacuum determination unit 44 determines whether the degree of vacuum of the condenser 13 stored in the memory is higher than a reference value or a reference range (whether it is close to atmospheric pressure) (step). S22).

  When the detected value is closer to the atmospheric pressure than the reference value or the reference range (YES in step S22), the flow control unit 43 increases the opening degree of the first valve 50 from the current state. Thereby, the flow volume of the seawater supplied to the condenser 13 is increased with respect to a predetermined reference flow volume (step S24). Therefore, the temperature of the condenser 13 decreases and the degree of vacuum of the condenser 13 changes in a direction approaching absolute vacuum. On the other hand, when the detected value is closer to the absolute vacuum than the reference value or the reference range (YES in step S23), the flow control unit 43 makes the opening degree of the first valve 50 smaller than the current state. Thereby, the flow volume of the seawater supplied to the condenser 13 is reduced with respect to a predetermined reference flow volume (step S25). Therefore, the temperature of the condenser 13 rises and the degree of vacuum of the condenser 13 changes in a direction approaching atmospheric pressure.

  Next, the degree-of-vacuum determination unit 44 checks whether or not a predetermined time has elapsed since the start of the increase or decrease in the flow rate of the seawater supplied to the condenser 13 (step S26). After a predetermined time has elapsed (YES in step S26), the vacuum degree determination unit 44 acquires the detection value of the pressure sensor 41 (step S27), and the vacuum degree of the condenser 13 returns to the reference value or the reference range. It is confirmed whether or not (step S28).

  When the degree of vacuum has not returned to the reference value or the reference range (NO in step S28), the flow rate control unit 43 maintains an increase or decrease in the flow rate of seawater. The process returns to step S21, the pressure data acquired in step S27 is stored in the memory, and the processes in and after step S22 are repeated. On the other hand, when the degree of vacuum has returned to the reference value or the reference range (YES in step S28), the process ends. By performing the above processing, the degree of vacuum on the outlet side of the steam turbine 12 in the steam circulation system 102 can be maintained within the allowable reference range.

  FIG. 6 is a flowchart showing details of the waste heat circulation system cooling water temperature control (second control) in step S30. The temperature determination unit 45 stores the temperature data acquired in the previous step S4 in a memory (not shown) (step S301). Next, the temperature determination unit 45 determines whether or not the temperature stored in the memory is higher than a reference value or a reference range (step S302). When the temperature is higher than the reference value or the reference range (YES in step S302), the flow control unit 43 determines whether or not the fifth valve 54 is open (step S303).

  When the fifth valve 54 is open (YES in step S303), the flow control unit 43 decreases the opening of the fifth valve 54 (step S306). Thereby, the flow volume of the cooling water which passes the short circuit piping 63 is decreased, and the temperature of the cooling water in the downstream junction part 602 of the waste heat circulation system 6 is reduced. On the other hand, when the fifth valve 54 is closed (NO in step S303), the flow control unit 43 increases the opening degree of the fourth and seventh valves 53 and 56, and the cooling water cooler 3 is connected to the young deep water cooling system. 7 and the flow rate of the cooling water in the waste heat circulation system 6 are increased (step S307). Thereby, the cooling water is cooled in the cooling water cooler 3, and the temperature of the cooling water in the downstream junction 602 changes in a decreasing direction.

  On the other hand, when the temperature is lower than the reference value or the reference range (YES in step S304), the flow rate control unit 43 indicates that the fourth valve 53 and the seventh valve 56 of the cooling water cooler 3 have the minimum opening. It is determined whether or not the vehicle is in operation (step S305).

  When the valves 53 and 57 of the cooling water cooler 3 are operated at the minimum opening (YES in step S305), the opening of the fifth valve 54 is increased (step S308). Thereby, the cooling water flow rate of the short circuit piping 63 is increased, and the temperature of the cooling water in the downstream junction 602 is increased.

  On the other hand, when the valves 53 and 57 of the cooling water cooler 3 are not operated at the minimum opening (NO in step S305), the flow controller 43 reduces the opening of the fourth valve 53 and the seventh valve 56, The flow rate of the seawater of the young deep water cooling system 7 and the cooling water of the waste heat circulation system 6 in the cooling water cooler 3 is reduced (step S309). Thereby, the cooling of the cooling water in the cooling water cooler 3 is suppressed, and the temperature of the cooling water in the downstream junction 602 can be increased.

  Next, the temperature determination unit 45 confirms whether or not the temperature control of the cooling water in the downstream merging unit 602 of the waste heat circulation system 6 has been performed for a predetermined time (step S310). After a predetermined time has elapsed (YES in step S310), the temperature determination unit 45 acquires the temperature detection value of the temperature sensor 42 (step S311), and the temperature of the cooling water in the downstream junction 602 of the waste heat circulation system 6 is the reference. It is confirmed whether or not the value or the reference range has been lowered (step S312).

  When the temperature of the cooling water has returned to the reference value or the reference range (YES in step S312), the process ends. On the other hand, when the temperature of the cooling water has not returned to the reference value or the reference range (NO in step S312), the process returns to step S301, the temperature data acquired in step S311 is stored in the memory, and step S302 is performed. The following process is repeated.

  As described above, according to the power plant G according to the present embodiment, the young deep water cooling system 7 for taking seawater from the young deep layer where the water quality is good and marine organisms such as jellyfish and shellfish hardly live. Since it is provided, marine organisms can be prevented from entering the power plant G, and marine organisms can be prevented from attaching and breeding to the condenser 13 and the cooling water cooler 3. Can be suppressed. Further, the supply amount control unit 4 performs the first control, so that the pressure in the steam circulation system 102 can be maintained within a predetermined range, thereby maintaining the vacuum efficiency of the steam turbine 12 at a high level. Can do. Furthermore, since the supply amount control unit 4 performs the second control, the temperature of the cooling water is maintained within a predetermined range, so that the cooling efficiency of the cooling water can be increased. In addition, the amount of seawater used is sufficient to maintain the pressure in the steam circulation system 102 within the predetermined range in the condenser 13, and the temperature of the cooling water within the predetermined range at the heat exchanging unit 31. Since the amount is sufficient to maintain, the amount of seawater used (water intake) can be minimized. In addition, the seawater temperature of the young deep water is considerably lower than that of the surface water, and the water temperature after use at the power plant G is not much different from the surface water. Therefore, the wastewater is discharged near the surface of the sea after waste heat recovery. It doesn't matter. In other words, warm drainage measures are virtually unnecessary. Accordingly, it is possible to suppress facility operation costs and the like while enjoying the merit of water intake from the above-mentioned younger generation.

  In addition, young deep water is rich in nutrient salts and contains rare metals. Therefore, the utility of the power generation system G can be further increased by extracting the nutrient salt from the young deep water after use in the power plant G and using it secondarily in the fishery or recovering the rare metals. Can be increased. Furthermore, an energy saving effect (carbon dioxide reduction effect) can be achieved by using the heat or cold of the young deep layer water for air conditioning.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this. For example, in the embodiment shown in FIG. 1, an example in which one cooling water cooler 3 is used is shown. In a general power plant, a plurality of cooling water coolers 3 are provided. In this case, one of the plurality of cooling water coolers 3 may be used for the waste heat power generation system 2 as in the present embodiment, and the rest may be used for cooling the waste heat of the power generation system 1.

  Moreover, in the said embodiment, cooling water was illustrated as a heat medium which circulates the inside of the waste heat circulation system | strain 6, and the cooling water cooler 3 was illustrated as a heat medium cooler. Instead of cooling water, cooling oil or cooling gas may be used as the heating medium of the waste heat circulation system 6, and the cooling medium or cooling gas may be cooled by the deep layer water in the heating medium cooler.

  Further, in the above embodiment, the supply amount control unit 4 performs both the condenser seawater flow rate control (first control) in step S20 of FIG. 4 and the heat circulation system cooling water temperature control (second control) in step S30. An example of executing is shown. Instead of this, the supply amount control unit 4 may be configured to execute at least one of the first control and the second control.

G Power plant 1 Power generation system 102 Steam circulation system 10 Boiler (heating source)
12 Steam Turbine 13 Condenser 2 Waste Heat Power Generation System 22 Waste Heat Turbine 23 Condenser 3 Cooling Water Cooler (Heating Medium Cooler)
31 Heat exchange part 4 Supply amount control part (control means)
41 Pressure sensor 42 Temperature sensor 5 Adjustment unit 6 Waste heat circulation system 61 Evaporator piping 62 Heat exchange unit piping 63 Short circuit piping 64 Outward piping 65 Return piping 6A Heat recovery unit 6B1 Heat release unit 6B2 Heat release unit 601 Upstream side junction 602 Downstream side junction 7 Waka Deep Water Cooling System 71 Intake piping 72 Condenser piping 73 Cooler piping 74 Condenser piping 75 Drainage piping

Claims (6)

A power generation system comprising a steam turbine, a condenser and a heating source, and a steam circulation system for circulating water or steam through them;
A system for generating power using waste heat of the power generation system, comprising a waste heat power generation system comprising a waste heat turbine, an evaporator and a condenser;
A heat medium cooler with a heat exchange section;
A heat medium circulation system that includes a heat recovery unit that recovers waste heat of heat generated by the operation of the steam turbine, and a heat release unit that releases heat in the evaporator and the heat exchange unit A thermal circulation system;
Young water deep water cooling system for taking sea water in the young deep layer, which is a lower layer range of 20 m to 200 m from the sea surface, and draining the sea water through the condenser, the condenser and the heat exchange unit;
Control means for controlling the flow rate of the seawater of the heat medium of the waste heat circulation system and the young depth water cooling system,
The control means includes
A first control for adjusting a flow rate of the seawater passing through the condenser of the young deep water cooling system in order to maintain the pressure in the steam circulation system within a predetermined range;
A second control for adjusting a flow rate of the seawater passing through the heat exchange section of the young deep water cooling system in order to maintain the temperature of the heating medium in the waste heat circulation system within a predetermined range; A power plant that performs at least one of them. The power plant according to claim 1,
The control means is a power plant that executes both the first control and the second control. The power plant according to claim 1,
The power plant in which the temperature of the cooling water introduced into the condenser is limited within a certain temperature range. The power plant according to any one of claims 1 to 3,
A pressure sensor disposed on an outlet side of the steam turbine of the steam circulation system;
When the detection value of the pressure sensor is lower than a predetermined reference value, the first control of the control means decreases the flow rate of seawater passing through the condenser with respect to a predetermined reference flow rate, and detects the detection. When the value is higher than the reference value, the power plant is a control for increasing the flow rate of the seawater relative to the reference flow rate. The power plant according to any one of claims 1 to 3,
The waste heat circulation system includes an evaporator pipe that passes through the evaporator, a heat exchange part pipe that passes through the heat exchange part, an upstream junction between the evaporator pipe and the heat exchange part, and the heat. A forward pipe connecting the recovery unit, a downstream pipe connecting the evaporator pipe and the heat exchange unit pipe, and a return pipe connecting the heat recovery unit,
A temperature sensor disposed in the return pipe and detecting the temperature of the heat medium;
The second control of the control means includes a control for increasing a flow rate of seawater passing through the heat exchange unit with respect to a predetermined reference flow rate when a detection value of the temperature sensor is higher than a predetermined reference temperature. Power plant. The power plant according to claim 5,
The waste heat circulation system further includes a short-circuit pipe that directly connects the upstream merging portion and the downstream merging portion,
The second control of the control means includes a control for increasing a flow rate of the heating medium passing through the short-circuit pipe when a detection value of the temperature sensor is lower than a predetermined reference temperature.

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